GPS devices have revolutionized the art and science of vehicle navigation. Besides providing navigational services, GPS units store information about recreational places, parks, restaurants, airports etc. which are useful to make travel decisions on the fly. On most occasions, the fastest or shortest route is the most sought after by users. Kabel et. al. in U.S. Pat. No. 7,386,392 B1 have described systems, devices, and methods for calculating a course for avoiding user identified criteria. A navigation device with route calculation capabilities includes a processor connected to an input and a memory that includes cartographic data and user identified criteria. A route calculation algorithm can be used to calculate a course between two or more waypoints based on the predefined user criteria of the cartographic data. Performing the route calculation algorithm includes analyzing the cartographic data with a preference for providing the course that identifies and avoids the user identified criteria. A display is connected to the processor and is capable of displaying the calculated route and cartographic data. The device is also adapted to dynamically analyze an area surrounding a present location for user identified criteria to avoid and display the results of the analysis.
Most known algorithms for determining routes typically draw upon digitalized map data, which exhibit digital forms of individual road segments. The algorithms for determining a route combine the road segments based on various criteria. In a simplest case, the shortest segment-based route is searched for, i.e., the road segments yielding the shortest route to be traveled are selected. Alternatively, algorithms oriented toward the expected time for traveling such a route are today commonly used in determining an optimal route. A route comprised of varying road segments is here selected based on the expected traveling time, and a route having the shortest expected time is computed. In modern navigation devices, a user can introduce preset options, in which the road segments to be considered for a route must also satisfy various presettable criteria. For example, current navigation systems can often make use of a stipulation that the route be picked without taking into account ferry connections or toll roads. Taken together, these stipulations yield the fastest possible trip or least expensive trip.
It may be desirable to automatically generate routes that incorporate other aspects, in particular have a high recreational value. In US Patent Application US2008/0004797 A1, Katzer describes a method for the automatic, computer-assisted determination of a route travelable by motor vehicles from a starting point to a destination point based on digitalized map data, wherein a computer acquires a starting point and destination point, and determines the route based on possible road segments, is expanded in such a way that the automatically generated routes have a high recreational value. To this end, it is proposed that the computer determining the route preferably incorporate those road segments into the route that exhibit a high number of curves. Curves are road segments in which the road follows curves. Curves with a narrower, i.e., smaller radius are preferred in US Patent Application US2008/0004797 A1. Curvy roads are often preferred in particular by those drivers who do not determine the route just based on getting from one location to another as fast or inexpensively as possible, but emphasize the pleasure of driving. This holds true especially for drivers of motorcycles, sports cars or cabriolets, since traveling on curvy roads imparts a sporty driving experience precisely in these motor vehicles, thereby incorporating an “entertainment” or “recreational value”. One way of automatically determining the curvy road segments is described and illustrated in US Patent Application US2008/0004797 A1. The focus is placed in particular on the curve radius as well, so that only those road segments are designated as having “a high number of curves” that have corresponding curves with small radii. In the final analysis, the desired driving feel depends on the experienced transverse accelerations that are simulated in the method described here, taking into account the circular radii and expected speeds. The greater the transverse accelerations, the more fun the drive, so that a minimum level is here selected for these transverse accelerations, serving as a minimum threshold for defining a road segment as “exhibiting a high number of curves” or “curvy”. Routes with a high recreational value can also essentially be compiled based on other criteria, e.g., the selection of road segments that are scenic, panoramic, or interesting from the standpoint of archaeological history or architecture. Comparable designations can already be found in classic maps, in which scenic roads can be marked green, for example.
What is essentially missing in the aforementioned inventions is that the panoramic or scenic value of routes is assessed based on legacy historical data gathered from maps, travel books, tourist guides and the likes. Today, there are millions of user contributed images available on the Web and a sizable (and increasing) number of them are associated with geographical information (geotags). This volume of user contributed data can be leveraged to generate “photogenic routes” from a source to destination. These routes take a traveler through the more “photographed routes” or routes which are likely to provide a traveler with opportunities to enjoy beautiful sceneries/locales and/or take high quality pictures.
The present invention relates to general navigation and in particular generating and suggesting photogenic route(s) from a starting location to a destination location using a GPS device, quality and content of images taken a priori along all possible routes from the starting location to the destination location. The invention also displays the distribution of scene categories that travelers are likely to encounter in these photogenic route(s). In the current invention, scene categories will refer to high level concept or scene classes which are commonly represented in pictures taken by people.